package com.tanhua.dubbo.server.api;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.convert.Convert;
import cn.hutool.core.util.ObjectUtil;
import cn.hutool.core.util.PageUtil;
import cn.hutool.core.util.StrUtil;
import com.alibaba.dubbo.config.annotation.Service;
import com.mongodb.client.result.DeleteResult;
import com.tanhua.dubbo.server.enums.IdType;
import com.tanhua.dubbo.server.pojo.FollowUser;
import com.tanhua.dubbo.server.pojo.Video;
import com.tanhua.dubbo.server.service.IdService;
import com.tanhua.dubbo.server.vo.PageInfo;
import org.bson.types.ObjectId;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.query.Criteria;
import org.springframework.data.mongodb.core.query.Query;
import org.springframework.data.redis.core.RedisTemplate;

import java.util.ArrayList;
import java.util.List;

/**
 * 小视频
 */
@Service(version = "1.0.0")
public class VideoApiImpl implements VideoApi{

    @Autowired
    private IdService idService;

    @Autowired
    private MongoTemplate mongoTemplate;

    @Autowired
    private RedisTemplate<String,String> redisTemplate;

    private static final String VIDEO_FOLLOW_USER_KEY_PREFIX = "VIDEO_FOLLOW_USER_";

    /**
     * 发布小视频
     * @param video
     * @return
     */
    @Override
    public String saveVideo(Video video) {
        //1. 校验这个视频对象是否符合要求  发布用户id，封面图片，视频文件
        if(ObjectUtil.isAllEmpty(video.getUserId(),video.getPicUrl(),video.getVideoUrl())){
            return null;
        }

        //2. 设置主键id
        video.setId(ObjectId.get());
        //3. 设置vid（推荐功能使用）
        video.setVid(idService.createId(IdType.VIDEO));
        //4. 设置时间
        video.setCreated(System.currentTimeMillis());

        //5. 保存到MongoDB中
        mongoTemplate.save(video);

        //6. 返回该视频的主键id
        return video.getId().toHexString();
    }

    /**
     * 查询小视频列表，先从redis中获取推荐列表，之后在从MongoDB中获取新发布的动态
     * @param userId
     * @param page
     * @param pageSize
     * @return
     */
    @Override
    public PageInfo<Video> queryVideoList(Long userId, Integer page, Integer pageSize) {
        PageInfo<Video> pageInfo = new PageInfo<>();
        pageInfo.setPageNum(page);
        pageInfo.setPageSize(pageSize);

        //从redis中获取推荐数据
        String redisKey = "QUANZI_VIDEO_RECOMMEND_" + userId;
        String redisValue = redisTemplate.opsForValue().get(redisKey);

        List<Long> vids = new ArrayList<>();
        int recommendCount = 0;
        if (StrUtil.isNotEmpty(redisValue)) {
            //手动分页查询数据
            List<String> vidList = StrUtil.split(redisValue, ',');
            //计算分页
            int[] startEnd = PageUtil.transToStartEnd(page - 1, pageSize);
            int startIndex = startEnd[0]; //开始
            int endIndex = Math.min(startEnd[1], vidList.size()); //结束

            for (int i = startIndex; i < endIndex; i++) {
                vids.add(Convert.toLong(vidList.get(i)));
            }
            recommendCount = vidList.size();
        }

            if (CollUtil.isEmpty(vids)) {
                //没有推荐或前面推荐已经查询完毕，查询系统的视频数据

                //计算前面的推荐视频页数
                int totalPage = PageUtil.totalPage(recommendCount, pageSize);

                PageRequest pageRequest = PageRequest.of(page - totalPage - 1, pageSize, Sort.by(Sort.Order.desc("created")));
                Query query = new Query().with(pageRequest);
                List<Video> videoList = this.mongoTemplate.find(query, Video.class);
                pageInfo.setRecords(videoList);
                return pageInfo;
            }

            //根据vid查询对应的视频数据了
            Query query = Query.query(Criteria.where("vid").in(vids));
            List<Video> videoList = this.mongoTemplate.find(query, Video.class);
            pageInfo.setRecords(videoList);

            return pageInfo;
    }

    /**
     * 根据视频id查询视频信息
     * @param videoId
     * @return
     */
    @Override
    public Video queryVideoById(String videoId) {
        return this.mongoTemplate.findById(new ObjectId(videoId), Video.class);
    }

    /**
     * 关注用户
     * @param userId 当前用户
     * @param followUserId 关注的目标用户
     * @return
     */
    @Override
    public Boolean followUser(Long userId, Long followUserId) {
        if (!ObjectUtil.isAllNotEmpty(userId, followUserId)) {
            return false;
        }

        try {
            //需要将用户的关注列表，保存到redis中，方便后续的查询
            //使用redis的hash结构
            if (isFollowUser(userId, followUserId)) {
                return false;
            }

            FollowUser followUser = new FollowUser();
            followUser.setId(ObjectId.get());
            followUser.setUserId(userId);
            followUser.setFollowUserId(followUserId);
            followUser.setCreated(System.currentTimeMillis());

            mongoTemplate.save(followUser);

            //保存数据到redis
            String redisKey = VIDEO_FOLLOW_USER_KEY_PREFIX + userId;
            String hashKey = String.valueOf(followUserId);
            redisTemplate.opsForHash().put(redisKey, hashKey, "1");

            return true;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return false;
    }

    /**
     * 取消关注用户
     * @param userId 当前用户
     * @param followUserId 关注的目标用户
     * @return
     */
    @Override
    public Boolean disFollowUser(Long userId, Long followUserId) {
        if (!ObjectUtil.isAllNotEmpty(userId, followUserId)) {
            return false;
        }

        if (!isFollowUser(userId, followUserId)) {
            return false;
        }

        //取消关注，删除关注数据即可
        Query query = Query.query(Criteria.where("userId").is(userId)
                .and("followUserId").is(followUserId)
        );
        DeleteResult result = this.mongoTemplate.remove(query, FollowUser.class);
        if (result.getDeletedCount() > 0) {
            //同时删除redis中的数据
            String redisKey = VIDEO_FOLLOW_USER_KEY_PREFIX+userId;
            String hashKey = String.valueOf(followUserId);
            redisTemplate.opsForHash().delete(redisKey, hashKey);

            return true;
        }

        return false;
    }

    /**
     * 是否关注该用户
     * @param userId 当前用户
     * @param followUserId 关注的目标用户
     * @return
     */
    @Override
    public Boolean isFollowUser(Long userId, Long followUserId) {
        String redisKey = VIDEO_FOLLOW_USER_KEY_PREFIX + userId;
        String hashKey = String.valueOf(followUserId);
        return redisTemplate.opsForHash().hasKey(redisKey, hashKey);
    }
}
